The Present Disclosure relates generally to the construction of plug connectors and, more particularly, to high-speed plug connectors having improved impedance characteristics.
Many different styles of cable connectors are known. One such connector is described in U.S. Pat. No. 7,175,444, the contents of which are incorporated by reference herein in its entirety. In the connector disclosed in the '444 patent, cable wires are connected to contact pads on a printed circuit board used as a mating blade of the connector. The wires are terminated to the contact pads in a termination nest area and then overmolded with plastic. The plastic has a higher dielectric constant than air and, as such, affects the impedance of the connector, typically by lowering it in that area. The resultant dip in impedance may be detrimental to the operation of the connector based upon its magnitude. At low operational speeds and data transmission rates, such as 1 Gbs, an impedance dip of greater than 8-10 ohms may not introduce excessive noise into the connector. However, at higher speeds and data transmission rates, such as upwards to about 8-12 Gbs, noise rises to a level where it becomes an issue. Large dips in impedance are conducive to the introduction of noise into the connector as well as crosstalk.
However, the use of plastic overmolding is desirable because it provides a reliable means for locating the wires and the circuit boards within an exterior housing, as well as forming a unitary connector structure. Additionally, plastic overmolding also provides strain relief which protects the joined or soldered connections to the printed circuit boards from direct pull forces on the cable. Further, removing the overmolded section leads to a non-unitary structure.
The Present Disclosure is therefore directed to a plug connector that has a desirable impedance profile, as well as one with a robust connector structure.